Understanding Tendinitis -- the Basics

What Is Tendinitis?

Tendinitis, now often referred to by professionals as overuse tendinopathy, is localized pain in or around a tendon, which is a band of fibrous tissue that connects muscle to bone and transmits the force and action of the muscle.

Tendons are designed to withstand bending, stretching, and twisting, but they can become inflamed from traumatic injuries that leave them with torn fibers or other damage (tendinitis) or, more commonly, fail to heal or scar following overuse (tendinosis). Some common examples of overuse include Achilles tendinopathy of the ankle in runners, rotator cuff tendinitis of the shoulder, and lateral epicondylitis, or tennis elbow.

The pain of tendinitis can be significant and worsens if damage progresses because of continued use of the joint. Most damage heals in about two to four weeks, but chronic tendinitis can take more than six weeks, often because the sufferer doesn't give the tendon time to heal. In chronic cases, there may be restriction of motion of the joint due to scarring or narrowing of the sheath of tissue that surrounds the tendon.

What Causes Overuse Tendinopathy?

Tendons can become damaged when overstressed from any activity. It used to be thought that they were inflamed, however, the tendon actually develops chronic degenerative changes. Weekend athletes, who exercise sporadically rather than regularly, often develop sore tendons. But by far the most common cause is repetitive stress -- using the same joints for the same stressful movements again and again. This happens not only in sports but also in many types of office work and other situations. Tendons are also more likely to become damaged by using inadequate equipment (such as old footwear), exercising in poor conditions, and with increasing age when tendons tend to lose their elasticity.